1. Field of the Invention
The present invention is related to a surgical instrument, and more particularly to an ergonomic and easy constructional surgical instrument for acetabular cup implantation.
2. Description of Related Art
The hip joint is the joint between the femur and acetabulum of the pelvis and combines with articular hyaline cartilage, synovial membrane and labrum to form a ball-like joint. It is a special type of ball and socket joint and its primary function is to support the weight of the body in both static (e.g. standing) and dynamic (e.g. walking or running) postures.
The normal hip functions as a “ball and socket” joint, allowing smooth range of motion in multiple planes in motion of human body. Any condition that affects either of these structures can lead to deterioration of the joint. This, in turn, can lead to deformity, pain, and loss of function. The most common condition affecting the hip in this way is osteoarthritis. Other conditions that may affect the hip adversely include inflammatory arthritis (rheumatoid arthritis, psoriatic arthritis, spondyloarthropathies, etc.), developmental dysplasia, childhood hip disorders (Legg-Calve-Perthes disease, slipped capital femoral epiphysis, etc.), trauma, neoplasms, and osteonecrosis. When the injury or disease occurs the damage component(s) can be rebuilt or replaced using appropriate orthopaedic implants. In the technique known as “Total hip replacement”, this involves surgical operation to clean femur and acetabulum, and then replace with artificial point.
A total hip artificial joint is a key prosthesis in the replacement operation. It consist of femoral stem, acetabular system (acetabular cup & acetabular liner & bone screw), Bipolar system (bipolar cup & bipolar liner), and metal ball head. The total joint replacement can require an acetabular cup component providing a bearing or articulating surface for the acetabulum and a femoral component providing an articulating surface for the femoral head. The acetabular cup and femoral components can generally be positioned relative to various portions of the associated anatomy in a substantially fixed manner. A liner fits inside the socket and allows the hip to move smoothly. A metal or ceramic ball that will replace the round head (top) of thigh bone. A metal stem is attached to the thigh bone to make the joint more stable.
It is key issue for medical personnel to insert the acetabular cup into the acetabulum. Medical personnel operate with the holder of acetabular cup inserter, which positions the acetabular cup by using screws to fix and insert acetabular cup inserter into the position of hip tissue of pelvis. After finishing insertion, the acetabular cup inserter is screwed to release the acetabular cup inside. Nevertheless, the acetabular cup inserters used nowadays are too structural complexes to handles easily; it brings no ergonomic resulting in difficulties to operate inserters.
In order to solve the problem(s), the present invention introduces a surgical instrument for acetabular cup implantation.